Engine afterburner control system



Oct. 16, 1962 c. w. MORRIS 'ENGINE AFTERBURNER CONTROL SYSTEM Filed Feb.21, 1961 s 2 H W E o WMQW UnitedStates Patent 3,058,298 ENGINEAFTERBURNER CONTRGL SYSTEM Charles W. Morris, 11769 Chenault St, LosAngeies 49, Calif. Filed Feb. 21, 1961, Ser. No. 90,675 3 Claims. (Cl.6tl2) In general this invention relates to a means and method forinsuring proper operation of spark-ignited combustion chambers whichtreat the exhaust gases of internal combustion engines. Such chambersare commonly referred to as afterburners. More specifically, thisinvention involves a new form of a dual insulated electrode spark plugadapted for use in an afterburner or other device. When used in anafterburner, the proper operation of such sparkplug controls theignition system of the internal combustion engine whose exhaust gasesare treated by said after burner.

It is generally known that the exhaust gases of internal combustionengines contain substantial amounts of hydrocarbons, carbon monoxide,oxides of nitrogen and other noxious components which contaminate thesurrounding air. In metropolitan areas, due to the very large number ofinternal combustion engines being used in cars, trucks and buses in arelatively small area, the atmospheric pollution from this source alonereaches relatively high concentrations. Such atmospheric contamination,popularly known as smog, has serious detrimental effects upon the healthof the population, animals and vegetation in such areas. These effectshave resulted in large expenditures of time and money directed to theelimination of smog, but to date the control of smog from the exhaust ofinternal combustion engines has been prohibitively expensive.

It is now generally known that the primary source of smog is theunburned hydrocarbon and carbon-monoxide content of exhaust gases.Consequently much effort has been directed toward completion of thecombustion process by passing the exhaust gases through a combustionchamber prior to release to the atmosphere. Such afterburners commonlyutilize spark-ignited combustion analogous to the combustion in theengine because of the outstanding advantages of simplicity and economywhen compared to other combustion processes such as catalyticcombustion.

However, the present spark-ignited afterburners have not attainedsufiicient reliability to insure that once installed they will completecombustion of the exhaust gases over long periods of time under alldriving conditions without frequent inspection. It must be rememberedthat in addition to the approximately six million new vehicles cominginto service each year, there are approximately ten times that number ofolder vehicles already in service. During operation, these vehicles aresubjected to extremely wide ranges of driving conditions. Likewise eachindividual vehicle is operated differently with respect to variablessuch as number of miles traveled each day and the number of stops andstarts. Installation of an afterburner has no meaning and fails toaccomplish the desired objective unless such device is actuallymaintained in operative condition during use of a vehicle. Periodicinspection of all vehicles has been sug gested, but to set up anadequate inspection system under divergent conditions of use wouldrequire an enormously expensive and time-consuming system which wouldgreatly complicate the solution of the smog problem.

As part of the present invention it has been found that the primarycause for malfunctioning of spark-ignited afterburners is impropersparking. At present, if the sparkplug in the afterburner is totallyinoperative or pro ducing weak, ineffective sparks, the only way toascertain this fact is to actually inspect it by removal and testing.

3,958,298 Patented Oct. 16, 1962 This procedure requires just the sortof frequent and expensive inspection with its attendant problems whichhave already been pointed out. The present invention completelyeliminates the inspection problem by making the ignition system for theinternal combustion engine depend cut on the proper sparking of theafterburner sparkplug. If the afterburner sparkplug is burned out, theengine fails to operate and the cause is quite simple to find. If theafterburner sparkplug is weak, the operation of the engine is markedlyalfected and again the cause is easy to determine.

In addition to the advantage of eliminating frequent inspections, thepresent invention also involves a sparkplug which greatly minimizesinduction effects which impair the efiiciency of sparkplugs nowavailable for use in afterburners. The sparkplug of the presentinvention is simple and economical to make. Also the sparkplug of thepresent invention gives spark points which promote sparking and produceslarger, more effective electrical discharge in the desired zone.

In general, the present invention comprises sparking means containing atleast two spaced, insulated electrodes with adjacent spark points in anafterburner receiving the exhaust gases from, an internal combustionengine. Preferably the sparking means comprises two non-parallel,spaced, elongated electrodes with spark points at their adjacent endsand terminals at their remote ends, with a single body of insulatingmaterial completely enclosing and separating the electrodes between thespark points and terminals. High voltage electrical impulses are supplied at regular intervals to one of said electrodes. These electricalimpulses are then transmitted to another of said electrodes by sparkingbetween the electrode spark points and then distributed to ignitionmeans in the internal combustion engine.

One feature of the present invention is that the electrical impulsesfrom the customary induction coil are received by one insulatedelectrode of the afterburner sparkplug, are transmitted to anotherinsulated electrode of the afterburner sparkplug by sparking and thenare sent to the customary distributor from the other electrode. Theprior art always grounded one of the electrodes of the afterburnersparkplug so that electrical impulses sent to the afterburner sparkplugcould not be further utilized and there was no way to know whether suchsparkplug was operating properly short of actual removal and testmg.

Another feature of the present invention is that the dual insulatedelectrodes are non-parallel so that any interaction between theelectro-magnetic or induction fields surrounding said electrodes isminimized and consequently the resistance to current flow and decreasedsparking caused be such that interaction is minimized. The reason thatthe interaction is minimized is that the angle between the electrodescauses the encircling electro-magnetic fields to be separated and alsoto contact at an angle. The metal collar which may be used to attach thesparkplug of the present invention to the afterburner is not anelectrode so it does not influence the operation of the sparkplug. Inaddition, such spacing insures edge-to-edge spark points which increasesthe intensity and effectiveness of the electrical discharge between thespark points.

The prior art utilized parallel coaxial electrodes with the outergrounded electrode forming a collar around the inner electrode and withsurface-to-surface spark points. Since the electro-magnetic field set upby the electrodes encircles the electrodes, the interaction between thefields in the prior art sparkplugs was at a maximum, i.e. the outergrounded electrode coincided exactly with the field set up by the innerelectrode.

An object of the present invention is to insure proper operation ofspark-ignited afterburners without the necessity of frequent inspection.

Another object of the present invention is to control the ignitionsystem of internal combustion engines through proper operation of theirassociated afterburner sparkplug. Still another object of the presentinvention is an afterburner sparkplug which efliciently, simply andeconomically permits control of the ignition system of its associatedinternal combustion engine.

Other objects and advantages of this invention will be readily apparentfrom the following description and draw ings which illustrate anexemplary embodiment of this invention.

In the drawings:

FIG. 1 represents a simplified schematic diagram of an internalcombustion engine with its associated ignition and exhaust systems,incorporating the present invention.

FIG. 2 represents an enlarged cross-section of the afterburner sparkplugshown in FIG. 1.

FIG. 3 is a bottom view of the sparkplug shown in FIG. 2.

As shown in FIG. 1, an exemplary system employing the present inventioncomprises an ignition system generally indicated at 1 which controls theoperation of an internal combustion engine 10 and an exhaust systemgenerally indicated at 20 which treats the combustion products from theinternal combustion engine 10. In ignition system 1, a source of lowvoltage such as a battery 2 is connected through a switch 3 to theprimary of an induction coil 4 and an automatic switch 5, usually calleda timer, which is opened at regular intervals by the operation of theengine 10. A complete electrical circuit is formed when switch 3 andtimer 5 is closed so that current may flow through induction coil 4. Acapacitor 6 is connected in parallel with timer 5 to absorb the energywhich would otherwise cause a small are when the contact points of timer5 are opened. The secondary of induction coil 4 is electricallyconnected by lead 4 to conduct the electrical impulses caused by timer 5and induction coil 4 to one electrode of afterburner sparkplug 7. Theother electrode of afterburner sparkplug 7 is electrically connected bylead 7' to a distributor 8 to conduct thereto the electrical impulsescaused by the sparking between the electrodes of sparkplug 7.Distributor 8 is in turn electrically connected to the sparkplugs 9 ofinternal combustion engine 10 and supplies energy to such plugs in adesired sequence and in timed relation to the rotation of the engine.

In the exhaust system 20, the exhaust gases from engine 10 are receivedin a manifold 21 and conducted to afterburner 22. The "afterburner 22may not only complete the combustion of the exhaust gases and reducetheir hydrocarbon and monoxide content but may also mufile the explosiveexpansion of exhaust gases from engine 10. The exhaust gases areconducted from after burner 22 by exhaust pipe 23 which may pass througha separate muffler if afterburner 22 does not include a mufiler.

When internal combustion engine 10 is started by using a starter motor(not shown) and closing switch 3, the battery 2 sends low voltagecurrent through induction coil 4 and timer 5 Where it is broken up intoelectrical impulses and converted into high voltage impulses. The highvoltage impulses from induction coil 4 are supplied to sparkplug 7 inafterburner 22 by means of lead 4'. These high voltage impulses aretransmitted to distributor 8 through lead 7 by means of sparking betweenthe electrodes of sparkplug 7. Distributor 8 shunts each impulse to thesparkplug in the particular cylinder ready to receive ignition action.The exhaust gases from engine 10 pass to afterburner 22 through manifold21. In afterburner 22, the combustion of the exhaust gases is completedby ignition with sparkplug 7.

It should be noted particularly that this method of engine cylinderignition makes such ignition wholly dependent on the proper sparking ofthe sparkplug in the afterburner. If the afterburner sparkplug isdefective in any Way, the engine operation will be markedly affected sothe owner of the vehicle will be forced to maintain the 'afterburnersparkplug in proper condition. In addition, periodic inspection becomesunnecessary since the engine operation itself afiords a constant,accurate indication of whether the afterburner is operating properly. Inthe prior art where the afterburner sparkplug Was grounded and theengine operated independently of it, periodic inspection was necessaryand even then the sparkplug could fail shortly after inspection andpermit smog discharge until the next inspection.

In FIGS. 2 and 3, an afterburner sparkplug 7 of the character adaptedfor use in the system shown in FIG. 1, is shown in great detail.Electrodes 30 and 30 are spaced and set at an angle to each other sothat their spark points 31 and 31 are adjacent while their terminals 32and 32', which are connected to leads 4' and 7' respectively, areremote. Electrodes 30 and 30' are preferably completely enclosed andseparated by a single body of insulating material 33 between their sparkpoints and terminals. Ceramic compositions resistant to hightemperatures and high temperature gradients, and having good dielectricproper-ties are generally employed for the sparkplug bodies. A spacingextension 33 from insulator 33 insures insulation between terminals 32and 32'. The annular ridge extension 33" from the insulator 33 forms aseat for an annular metal collar 34 which surrounds insulator 33adjacent the electrode spark points 31 land 31. Collar 34 is clamped bya flanged ring 35 to ridge extension 33" and externally threaded tofacilitate attachment of sparkplug 7 .to aftenburner 22.

In general, the sparkplug of the present invention may be made of thesame materials presently used to make the sparkplugs which are alreadywell known in the prior art. The spark gap between the insulatedelectrodes of the spark-plug will vary depending on the nature of thegaseous mixture in the afterburner to be ignited but usually will beconsiderably greater than those presently used in sparkplugs in theinternal combustion engine. The angle between the insulated electrodesof the sparkplug may vary depending on the relative importance ofreducing the resistance to current flow in the electrodes and makes thesparkplug compact. As the angle between the electrodes is increased, theinteraction between the electromagnetic fields surrounding saidelectrodes is decreased but the sparkplug itself becomes larger. Ingeneral it is preferred that the angle be from 10 to 30, most preferablyabout 20.

The present invention is subject to many modifications and variations.For example, a magneto system may replace the battery and coil system asa source of high voltage electrical impulses to the afterburnersparkplug. Also,.althougl1 the invention has been exemplified by using asingle, dual insulated electrode sparkplug in the a-fterburner, severalof such sparkplugs may be used. In addition, each sparkplug may havemore than two insulated electrodes.

As exemplified, the non-parallel, dual insulated electrodes of thesparkplug of the present invention lie in the same plane. However, suchelectrodes may be skew as long as they are enclosed in a single body ofinsulating material and encircled by a single metal collar.

The foregoing description and examples are only illustrative of thepresent invention and are not limitations on its scope. All alterations,modifications and variations of the present invention which are obviousto those skilled in the art or come within the scope of the followingclaims are considered as part of the present invention.

I claim:. a

1. In combination with a multi-cylinder internal combustion engineincluding an ignition system and a sparkignited :afterburner receivingthe exhaust gases from said engine the provision of: a sparkpluginserted in said afterburner containing two spaced insulated electrodeswith adjacent spark points; means operatively connected to one of saidelectrodes for supplying at regular intervals high voltage electricalimpulses; and means operatively connected to the other of saidelectrodes for distributing said electrical impulses in set sequence toignition means in the engine cylinders whereby operation of saidinternal combustion engine is controlled by the proper sparking of theafterburner sparkplug so that the need for frequent inspection of saidafter-burner is eliminated.

2. In combination with an internal combustion engine including anignition system and a spark-ignited afterburner receiving the exhaustgases from said engine the provision of: sparking means in saidafterburner comprising at least two spaced insulated electrodes withadjacent spark points; means operatively connected to at least one ofsaid electrodes for supplying at regular intervals high voltageelectrical impulses; and means operatively connected to at least oneother of said electrodes, for distributing said electrical impulses toignition means in the internal combustion engine; whereby operation ofsaid internal combustion engine is controlled by the proper sparking ofthe afterburner sparkplug so that the need for frequent inspection ofsaid afterbu-r-ner is eliminated.

3. In combination with a multi-cylinder internal combustion engine,including an ignition system and a sparkignited afterburner receivingthe exhaust gases from said engine, the provision of: a sparkpluginserted in said aftenburner comprising two non-parallel, spaced,elongated electrodes with spark points at their adjacent ends andterminals at their remote ends and a single body of insulating materialcompletely enclosing and separating said electrodes between said sparkpoints and said terminals; means operatively connected to the terminalof one of said electrodes for supplying at regular intervals highvoltage electrical impulses; and means operatively connected to theterminal of the other of said electrodes for distributing saidelectrical impulses in set sequence to the ignition means in the enginecylinders whereby operation of said internal combustion engine iscontrolled by the proper sparking of the afterburner sparkplug so thatthe need for frequent inspection of said afterburner is eliminated.

References Cited in the file of this patent UNITED STATES PATENTS1,560,512 Hirsch Nov. 3, 1925 1,848,065 Rabezz-ana Mar. 1, 19322,806,346 Clayton Sept. 17, 1957 2,895,292 Wentworth July 21, 19592,937,490 Calvert May 24, 1960

